The present invention concerns testing the reliability of processes performed in constructing a printed circuit board.
Printed circuit boards are often processed using automated processing equipment. When setting up such automated processing equipment it is generally necessary to test the automated processes before using the equipment to produce printed circuit boards to be distributed commercially.
The testing generally includes checking the integrity of the soldering process. This includes assuring that when soldering parts to the printed circuit board connections are strong and reliable and that parts are not damaged during the soldering processing. Additionally, it is necessary to verify that, after cleaning is completed, the soldering joints are clean and there is no remaining contaminants which can cause shorts. Also there is a need to test the reliability of the solder joints under environmental stress conditions. If the automated test equipment is to be used with printed circuit boards of different sizes and shapes, it is necessary to perform testing on printed circuit boards which are of similar size and shape as production printed circuit boards.
In order to test automated processing equipment, test cards are often used. Existing test cards are typically fabricated with hot air solder leveling. These test cards include daisy-chain patterns. The daisy chain patterns allow for continuity testing of soldered packages. In order to perform such testing, integrated circuit packages, which are specially designed for testing automated processing equipment, are soldered to the test cards. After the assembly process is finished, an ohmmeter is used to determine whether the electrical connections are complete.
While existing test cards are useful in testing automated processing equipment, the currently available cards are limited in the available size of cards, are limited in package selection and are limited in the types and versatility of testing that may be performed.